In prior art methods of attaching a counter weight to a rotor of an electric motor, the counter weight can be either installed in a receptacle in the rotor end ring, or mechanically attached to the end ring. A shaft counter weight is typically mechanically attached to the motor shaft in a spaced-apart relation from the rotor by heating the counter weight and placing it over a cold rotor shaft. When the shaft counter weight cools, a pressure bond is formed between the shaft counter weight and the rotor shaft, thus yielding a rotor in which the shaft counter weight is mechanically attached to the rotor shaft.